Db. Chesnut, An electron localization function investigation of bonding in some simple four-coordinate nitrogen and phosphorus compounds, HETEROAT CH, 11(5), 2000, pp. 341-352
The bonding in some simple four-coordinate species involving nitrogen and p
hosphorus has been studied by the electron localization function (ELF) appr
oach and compared to that in their conventionally singly and doubly bonded
counterparts. Despite evidence suggesting the presence of a conventional mu
ltiple bond in certain cases of the four-coordinate species, the ELF study
shows this not to be the case. Rather the situation is better pictured as,
for example, in the case of H3PCH2 as
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where both ionic and covalent interactions are present, a type of bond we t
erm cov-ionic. While the ionic interaction is generally strong, the covalen
t part can be weak, as in the case of the four-coordinate nitrogen compound
s, or strong as in the case of the four-coordinate phosphorus species. The
quantum mechanically determined properties of the cov-ionic bonded compound
s ave consistent with this picture. (C) 2000 John Wiley & Sons, Inc.